Artificial lung

Abstract

An artificial lung comprises a venous blood reservoir to receive and store venous blood. A heat exchanger communicating with the venous blood reservoir receives the venous blood so the blood temperature is regulated by heat exchange through a wall between flowing water and the venous blood. A blood oxygenator concentrically disposed within a hollow space of said heat exchanger comprises a cylindrical body defining a cylindrical space and at least one gas permeable membrane separating said cylindrical space into a first space and a second space. The first space receives the venous blood from the heat exchanger and the second space communicates with an oxygenating gas feed line so that the blood is oxygenated through the gas permeable membrane.

What is claimed is: 
     
       1. An artificial lung comprising: (a) a venous blood reservoir to receive and reserve venous blood;   (b) a heat exchanger comprising an outer cylindrical wall, an inner cylindrical wall, and at least one heat exchanger tube having a tube wall, said inner and outer cylindrical walls being disposed coaxially to form a tubular space therebetween, said at least one heat exchanger tube being disposed within said tubular space communicating with a feed water line to receive water of a predetermined temperature, and said tubular space outside said at least one heat exchanger tube communicating with said venous blood reservoir to receive venous blood so that the temperature of venous blood is regulated by means of a heat-exchange through said tube wall between water and venous blood, wherein said venous blood reservoir comprises a downtube, a reserve chamber, a diaphragm having means defining at least one aperture, and a cylindrical filter, said downtube leading the venous blood into said reserve chamber, said reserve chamber being covered by said diaphragm so that the venous blood is contained therein and overflows through said at least one aperture, said cylindrical filter covering an upper area of said reserve chamber so that the overflowed venous blood is contained temporarily therein and oozes therethrough gradually; and   (c) a blood oxygenating means, disposed within said inner cylindrical wall, comprising a cylindrical body defining a cylindrical space and at least one gas permeable membrane separating said cylindrical space into a first space and a second space, said first space being arranged to receive said venous blood from said heat exchanger and said second space communicating with an oxygen containing gas feed line so that blood is oxygenated through said at least one gas permeable membrane.   
     
     
       2. An artificial lung according to claim 1, wherein said removes impurities and bubbles, which may be contained in the venous blood. 
     
     
       3. An artificial lung according to claim 1 or 2 wherein the reserve chamber, diaphragm and filter are positioned above said heat exchanger, venous blood being enabled thereby to pass through said filter by virtue of gravity force. 
     
     
       4. An artificial lung according to claim 1, wherein said heat exchanger tube is wound around said inner cylindrical wall helically so as to generally fill said tubular space formed between said outer cylindrical wall and said inner cylindrical wall. 
     
     
       5. An artificial lung according to claim 4, wherein an outer diameter of said heat exchanger tube is generally equal to a thickness of said tubular space formed between said outer cylindrical wall and said inner cylindrical wall so that the venous blood supplied to said heat exchanger flows helically through a space formed between adjacent windings of said heat exchanger tube while heat exchanging through said tube wall. 
     
     
       6. An artificial lung according to claim 1, wherein said blood oxygenating means comprises upper and lower partitions closing upper and lower ends of said cylindrical body respectively, and said at least one gas permeable membrane is in the form of a prescribed number of hollow fibers, upper and lower ends of each of said hollow fibers being received in a leak-tight manner by each of said upper and lower partitions, respectively, so that said first space corresponds to a space formed within said cylindrical body and said second space corresponds to a space formed inside said hollow fibers communicating with a space over said upper partition and a space below said lower partition. 
     
     
       7. An artificial lung according to claim 6, wherein said hollow fibers form a plurality of fiber bundles composed of a plurality of said fibers, said bundles being wound spirally around an axis of said cylindrical body in a plurality of layers, wherein the direction of winding for adjacent layers interchanges layer by layer so that narrow open spaces are formed between said hollow fibers, and fiber bundle layers. 
     
     
       8. An artificial lung according to claim 7, wherein the outermost diameter of said layers is generally equal to the inner diameter of said cylindrical body, a venous blood inlet is formed at one of upper or lower ends of said cylindrical body to receive the venous blood, and an arterial blood outlet is formed at the other of said upper or lower ends of said cylindrical body for exit of arterial blood so that the venous blood flows from said venous blood inlet to said arterial blood outlet through said narrow open spaces while capturing oxygen therein. 
     
     
       9. An artificial lung according to claim 6, 7 or 8, wherein said at least one gas permeable membrane is made of a bio-compatible material selected from the group consisting of silicon membrane, polycarbonate membrane, porous polyolefin membrane, regenerated cellulose membrane, polysulfon membrane, porous nylon membrane, porous polyester membrane, porous acrylic membrane, and porous fluorine resin membrane.